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| Line 4: |
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| It is possible to enable the modem with:<syntaxhighlight lang="nix"> | | It is possible to enable the modem with:<syntaxhighlight lang="nix"> |
| networking.modemmanager.enable = true; | | networking.modemmanager.enable = true; |
| </syntaxhighlight>A good rule of thumb is to use NetworkManager as much as possible and rely on ModemManager functionality directly only when necessary (e.g., when having to insert a PIN to unlock the SIM card). | | </syntaxhighlight>A good rule of thumb is to use NetworkManager as much as possible for WWAN functionality and rely on ModemManager functionality directly only when necessary (e.g., when having to insert a PIN to unlock the SIM card). |
| | |
| == Tips and Tricks ==
| |
| | |
| === Prevention of WWAN connection on boot ===
| |
| Due concerns related to tracking and privacy, it may be wished to never automatically establish a cellular connection on boot. The custom Serviced service below allows to achieve exactly this goal.<syntaxhighlight lang="nixos"># Ensure that the modem does not establish a cellular connection
| |
| # on boot.
| |
| systemd.services.NetworkManager-radio-wwan-initial-setup = {
| |
| description = "Disable WWAN radio on first ModemManager start";
| |
| wantedBy = [ "multi-user.target" ];
| |
| before = [ "ModemManager.service" ];
| |
| after = [ "NetworkManager.service" ]; # Wait for NetworkManager
| |
| requires = [ "NetworkManager.service" ]; # Ensure NetworkManager is running
| |
| | |
| serviceConfig = {
| |
| Type = "oneshot";
| |
| RemainAfterExit = true; # The service won't run again on successive ModemManager activations.
| |
| ExecStart = "${pkgs.networkmanager}/bin/nmcli radio wwan off";
| |
| };
| |
| };</syntaxhighlight>Note that the state of the cellular connection will be retained even if <code>ModemManager</code> is restarted (as long as the system has not been rebooted).
| |
| | |
| == Troubleshooting ==
| |
| | |
| === Unreliable suspend/resume ===
| |
| Some modems, such as the Fibocom 350-GL, cause the system to automatically wake up from sleep. The behavior is inconsistent: sometimes it happens immediately, but it can also happen a few seconds or minutes after the machine is in suspended. Other times the machine correctly stays in sleep mode and does not wake up. Other times a loop of continuous suspensions and resumes is experienced.
| |
| | |
| As a workaround to the unreliability of such WWAN modules, the user needs to stop the <code>ModemManager</code> service before sleep. At this point, suspend should no longer cause the problems mentioned above. The user needs to restart the <code>ModemManager</code> service once the computer is resumed if they intend to connect to cellular data.
| |
| | |
| It is possible to automate this behavior by creating tailored Systemd services:<syntaxhighlight lang="nixos">
| |
| # Stop ModemManager before sleep.target is reached
| |
| # due to a bug with the WWAN module, which otherwise
| |
| # wakes up the system immediately after suspend.
| |
| systemd.services.ModemManager-stop-before-sleep = {
| |
| wantedBy = [ "sleep.target" ];
| |
| before = [ "sleep.target" ];
| |
| | |
| serviceConfig = {
| |
| Type = "oneshot";
| |
| ExecStart = "${pkgs.systemd}/bin/systemctl stop ModemManager.service";
| |
| };
| |
| };
| |
| | |
| # Restart ModemManager shortly after resume from suspend.
| |
| # This way the modem can be easily enabled within
| |
| # the desktop environment's networks' applet or the CLI.
| |
| systemd.services.ModemManager-restart-after-resume = {
| |
| description = "Restart ModemManager after resume";
| |
| wantedBy = [ "post-resume.target" ];
| |
| after = [
| |
| "systemd-suspend.service"
| |
| "systemd-hibernate.service"
| |
| "systemd-hybrid-sleep.service"
| |
| ];
| |
| | |
| serviceConfig = {
| |
| Type = "oneshot";
| |
| ExecStart = "${pkgs.systemd}/bin/systemctl restart ModemManager.service";
| |
| };
| |
| };
| |
| </syntaxhighlight>
| |
ModemManager is a DBus-activated daemon which manages cellular modems (2G, 3G, 4G and 5G) and establishes cellular data connections.[1]
Configuration
It is possible to enable the modem with:
networking.modemmanager.enable = true;
A good rule of thumb is to use NetworkManager as much as possible for WWAN functionality and rely on ModemManager functionality directly only when necessary (e.g., when having to insert a PIN to unlock the SIM card).
